And in his days Rav Hilai ben Mar Rav Chanina became head of the yeshiva in Sura in year 4556 for three and a half years until year 4560 [(and Shada"k page 58, heading 272, says Rav Yosef was in Pumbedita and Rav Hilai was in Mata Mechasia, they received in year 4596 and it is an error of 69)].